There are people on here being sarcastic if you didn't pick that up, playing a guitar won't help, that's ridiculous to flush for 15 weeks considering plants usually only flower for 8 -12 weeks, also you will not get a pound. it's really hard to say what your yeild will be, I'm guessing maybe an ounce per plant, just looking at the size. you will have to show us better pictures of them to tell you how to close to harvest you are, but even then we can only estimate. the most accurate way to check if a plant is done is to use a jewelers microscope and check the trichs color. if they're clear, your not even close, if some are milky and some are amber colored you are almost there.